Metal weather strip



A .25,1936. A. M. LANE 2 2,052,032

METAL WEATHER STRIP Filed Dec. 9, 1955 O W a m 1 /15 A'r TOENEYJ.

Patent Aug. 25, 1933 v htEZdtt 7 mass. was Alfred M. Lane, StJlLouis ilounty, lilo, assignor to Monarch Metal Weatherstrip Corporation; 7 St. Louis, Mo, a corporation oi o Application December e, not, serial No. scan could heretofore be successfully used for such metal weatherstrlps are zinc and bronze, each of which has many properties that tend to fit them for such purpose. It is important that the metal shall besuitable for shaping rigid grooves therein by rolling or other ordinary manufacture opera- 7 tion, without substantial distortion, and that the metal withstand bending, the finished weatherstrip in some cases having portions doubled bacis against each other. it is also important that the dd metal have a negligible amount of creep at the operating stresses and under normal operating temperatures to which weatherstrips are subiected so that the finished weatherstrlps shall be resilient, capable oi sliding on each other without excessive friction and without gelling the sur- Liaces thereof and resistant to atmospheric conditions. In addition to these properties, which are possessed by zinc and certain bronzes to a prac: tlcable extent, it is desirable that the metal should m be oi an ornamental color and that it should re sist acculation of dirt thereon and that it should be more economical. The principal ob" ject oi the present invention is to produce metal weatherstrips that will embody all oi these properties. The invention consists principally in metal weatherstri made of strips of alumin alloy having the above mentioned characteristics and having an oxide coating and impregnated with paramn or. other material having lubricating properties. The term oxide coating" as used herein defines those oxide coatings which are produced on the surface oi aluminum or its alloys by the action of some chemical agent with or without the aid oi the electric current. It does not include the very. thin film of alumin 'ornde which is normally formed upon the metal by contact with the air. As at present advised, sulphurlc acid is the preferred oxide coating ml. inc agent, but there are manyother chemicals and chemical agents which produce, either with or without the external application oi electrical energy, an oxide coating upon the surface of aid-- minum and its alloys. While all such'coatings are similar in chemical composition their physical M properties reflect to some extent those oi the oxide coating forming agent which is used. Chro mic acid and oxalic acid are examples of oxide coating forming agents which with the use of externally applied electrical energy produce satisfactory coatings for my purpose. An example of 5 an oxide coating forming agent which may be used without the application of electrical energy is a mixture of sodium carbonate and potassium dichromate. d

In the accompanying drawing which illustrates 10 my .nventlon as embodied in almetal Weatherstrip of old type, I

'i ig. i is a perspective View of the groove strip, Fig. 2 is a perspective View of the head strip,

- and 15 Fig. 3 is a sectional view of the assembled eatherstrip mounted in a window.

The metal Weatherstrip illustrated in the accompanying drawing comprises a groove strip l and a bead strip 2. The bead strip has a portion I of the metal shaped into a longitudinal head or rib whose outer portion is of circular or pearshaped section spaced from the body of the strip by a short neck or connecting portion. The groove strip has a portion formed into a longitudinai groove of proper size and shape to ht 'ireely over the bead of the bead strip. The construction described is typical of existing weatherstrips and may be modified in accordance with coon practice. my

Accorp to the present invention, the groove strip and the bead strip are made of strips of aluminum or aluminum alloy whose contacting surfaces have been elven an oxide coating having a depth of one to two ten thousandths of an inch. .35

coating is very hard and constitutes a continuous coating over the surface of the aluminum, to which it adheres with great tenacity. This aluminum oxide surface is minutely porous, that is, it is filled with a multiplicity of very minute to pores. The oxide coating is indicated by C in the drag, the thickness thereoi being exaggeratcd for purposes of illustration.

A suitable a1 a; num alloy for the purpose is one containing small quantities of magnesium (2.5%

being a satisfactory content) with or without smaller quantities of chromium (25% being a satisiactory content).

a suitable process for producing the oxide coating on the aluminum or aluminum alloy is to treat the material anodically with low working voltages (say from f) to 20 volts) in a bath of sulphuric acid having a concentration of from 15 to 35 percent by weight.

After the material has been given its oxide coating, it is treated with paraflin, greasy matter such as lanolin or other lubricating substance. I prefer to dip the material into a bath of parafiln at a temperature high enough to liquefy the paraflln. The material is then cooled and the excess paraflln is then wiped ofl. If the aluminum has been treated in strip form, it is ready for manufacture into metal weather-stripping, if in sheet form, it must first be cut into strips.

Aluminum weatherstrips made in accordance with my invention and having on their surface an oxide coating impregnated with a lubricant are capable of sliding one on the other without excessive friction and without. surface galling.

They are resistant to atmospheric condition and in fact, the wear due to this sliding action is slower than in the case of zinc and bronze strips. Among the advantages of weatherstrips made of paraflined and oxidized aluminum alloy are the following: They require less force to slide sashes equipped therewith; are more durable than zinc and bronze strips; they are substantially free from corrosion and burnishing; they have a pleasing color; they tend to repel ordinary dirt and are more readily cleanable than zinc and bronze.

While I have had very satisfactory results with impregnating a surface portion of the coated aluminum alloy with a solution of paramn in naptha having specific gravity of .74 degrees Baum, (ten percent by weight of paraflin in naptha) I do not wish to be restricted to such paraflln. The surface portion of the coated aluminum alloy, with its highly minutely porous structure, has a high capacity for absorbing and retaining oily and greasy matter. In fact I have found that it will take up and retain carbon black or finely divided graphite in suiilcient quantities to overcome the tendency for strips to gall and stick together. Graphite and paraflln are of mineral origin and, together with carbon black, have the important property of being inert as to oxygen at atmospheric temperature, whereas many animal and vegetable oils oxidize and become gummy whenexposed to the atmosphere for a considerable length of time. Likewise, parafiln, graphite and carbon black are unaffected by or highly resistant to atmospheric gases such as carbonic acid, sulphuric acid and ammonia.

The term aluminum in the claims isflto be understood as meaning either aluminum alloy or aluminum.

' What I claim is:

1. A metal Weatherstrip consisting of aluminum whose surface portion has an oxide coating impregnated with a lubricant which-is resistant to reaction with atmospheric gases.

2. A metal Weatherstrip consisting of aluminum whose surface portion has an anodic oxide coating impregnated with -a lubricant which is inert as to oxygen at atmospheric temperature.

3. A metal Weatherstrip whose body consists of aluminum having a layer of highly and minutely porous oxide of aluminum thereon, said aluminum oxide being impregnated with oily or greasy material of mineral origin.

4. A metal Weatherstrip whose body consists of aluminum having a layer of highly and minutely porous oxide of aluminum thereon, said aluminum oxide being impregnated with paraffin.

5. A metal Weatherstrip whose body consists of formed aluminum having a layer of highly and minutely porous oxide of aluminum thereon, said aluminum oxide being impregnated with carbon black.

ALFRED M. LANE. 

